Usual sleeping bags are of course known, formed by a sole flexible textile panel that is turned down on itself so as to constitute a sleeping space, closed for instance by a zip fastener. Alternately, such sleeping bags can be formed by several flexible panels that are put together, for instance by sewing, so as to constitute said sleeping space.
When such a sleeping bag is used to sleep directly on the ground, when bivouacking for instance, the user would rather use a mattress, for obvious comfort reasons.
The user should thus carry a small mattress, or a groundsheet, that he could arrange on the ground, and on which he could lay his sleeping bag.
One of the issues that is then raised is that the sleeping bag and the mattress are not necessarily adapted to each other, and that, when the user is asleep, the sleeping bag tends to slide outside the mattress or the groundsheet.
Alternate solutions are known, that consist in a sleeping bag comprising a reception pocket in which a mattress can be inserted. This is, for instance, the case of the solution described in FR 2 922 739.
It is possible to use such a sleeping bag in a first configuration with the mattress, and in a second configuration without the mattress. The sleeping bag comprises a reception pocket able to receive the mattress in the first configuration. The reception pocket shows an introduction opening for the mattress and is provided with securing means that enable the mattress to stay in the reception pocket in the first configuration.
One of the issues raised by such a sleeping bag is that, when the user wants to use his sleeping bag without the mattress, for instance when he sleeps in a refuge in which there is already a mattress, the empty reception pocket forms a disturbing extra material. This extra material is necessary for supporting the mattress in the first configuration, but is not adapted in the second configuration.
As a matter of fact, the extra material involves a bigger sleeping bag, which as a matter of fact involves in turn heat losses due to the air blades that have formed in the part of the sleeping space that is not filled by the user's body.
Moreover, this extra material under the sleeping bag involves a discomfort mainly located in the back area of the user.
Also, many other solutions combining a sleeping bag and a mattress jeopardize the ease of the user to move in the sleeping bag. Indeed, the addition of the mattress often involves a material tension or a blocking of the sleeping bag in a given position, and thus a decrease in the freedom of movement. This is in particular the case for the solution described in WO 0228239.
It is therefore an objective of the present invention to solve these issues among others.